Relating plasma processing, surface morphology, and electronic properties of nanomaterials

Abstract

Current approaches for analysis of the interrelations among plasma processing, morphological characteristics, electronic and optical properties of nano-structured materials are reviewed briefly. Practical implementation of these approaches is demonstrated for the cases of the plasma-assisted formation of silicon–germanium (Si1−x Ge x , 0 ⩽ x ⩽ 1.0) nano-structures on Si substrates with different crystalline orientations. Both numerical simulations and experimental studies on the effects of plasma parameters, germanium concentration, boron doping, crystalline orientations of the substrate on low-temperature photoluminescence (PL) of the Si1−x Ge x structures are considered. Different mechanisms of Si1−x Ge x morphology formation (e.g. traditional Stranski–Krastanov route as well as new approaches like cluster fluxes created in the plasmas) are compared; the latter ones are more flexible and exhibit wider range of the potential applications. Furthermore, effects of morphological characteristics and phonon confinement as well as energetic characteristics of the optic and acoustic phonons on the PL and electronic parameters of the experimentally studied nano-structures are analysed within the generalized Skettrup model and ‘displaced oscillator’ approximation.

Plasma nanoscience: from nano-solids in plasmas to nano-plasmas in solids

“…Due to the overwhelming complexity, only phenomenological or process-specific links presently exist. An interesting methodological approach to link the process parameters, morphological, and electronic properties of silicon-germanium (Si 1−x Ge x , 0 ≤ x ≤ 1.0) nanostructures produced using plasmas has recently been proposed [175]. In particular, the effect of the QD-morphology-controlled density of the electron trap states on the photoluminescence intensity can be approximated as [175]…”

Plasma effects in semiconducting nanowire growth

“…The primary reason for that is the ubiquitous utility of this Si precursor in the microelectronics industry. 28,32 However, silane is extremely toxic and also flammable in open air, which creates significant safety issues and increased infrastructure costs. Although previously used for Si nanowire production, plasma GT and s P GT in (d) quantify the time delay induced by the GT effect, while the subscripts C and P refer to the CVD and PECVD cases, respectively.…”

“…These applications encompass the more traditional semiconductor structuring and processing for nanoelectronics and a more recent expansion into materials, devices and processes for energy, environment, health care, security, and other sectors. [19][20][21][22][23][24][25][26][27][28][29][30][31][32] In many cases, for a large number of materials systems of different dimensionalities, it was proven that plasmabased processes may help to solve many significant problems that are otherwise difficult or challenging to overcome.…”